This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Mechanosensitive channels are involved in the touch and hearing in animals and osmoregulation in bacteria. MscL is a large-conductance mechanosensitive channel membrane protein which directly responds to membrane tension and serves as "emergency relief valve" to rescue bacteria under osmotic shock. MscL from Mycobacterium tuberculosis was found to be a pentamer while there might be other species form a different state of oligmer. Through SAXS, it may be possible to identify the oligomeric state of MscL from different species of bacteria and function relevant comformational change.